My left testicle

So, I've been having irratation in my downstair apartment for a couple of days now. My left testicle is red and sore. I've never had anything like this. It doesn't hurt too much or anything but I'm worried. For info, I'm a male 26y. Been married over a year now and never had this problem before. What should I do? Also, be free to ask me anything. I hope this is isn't something serious.